import java.util.Scanner;

/**
 * Created with IntelliJ IDEA.
 * Description:
 * User: 25228
 * Date: 2024-09-30
 * Time: 19:04
 */
public class Main6 {
    public static void main(String[] args) {
        Scanner in=new Scanner(System.in);
        double M = in.nextDouble();
        double init = in.nextDouble();
        double finalT = in.nextDouble();
        QCalculator qc = new QCalculator();
        System.out.printf("%.2f", qc.calQ(M, init, finalT));
    }
}


class QCalculator {
    public double calQ(double M, double initTemp, double finalTemp) {
        return M*(finalTemp-initTemp)*4184;
    }
}

